On September 19, 1783, French scientist Pilâtre de Rozier launched the first hot air balloon, called Aerostat Reveillon, which carried a sheep, a duck, and a rooster.
The balloon stayed in the air for 15 minutes before crashing back to the ground. The sheep, called Montauciel, was believed to have a reasonable approximation of human physiology.
The balloon is lifted by hot air and also has a compartment of “lighter-than-air” gas, like helium or hydrogen, in the top of the balloon. The sheep, duck, and rooster were all used to test hot air balloons before humans went up in them.